Post Merger Integration Strategy

Most deals don't fail at the term sheet. They fail in the first 100 days.‍

The synergy model was sound. The diligence was clean. Then integration started—and the value started leaking. Customers got nervous, key people walked, two operating models collided, and the timeline everyone agreed to in the data room quietly slipped a quarter, then two.

Stonehill exists to close that gap. We are the post-merger integration firm built specifically for PE-backed and founder-led middle market companies—and we turn the deal thesis into realized value before the value walks out the door.

Stonehill is the firm that makes middle market mergers work.

Why middle market integrations break ‍

The middle market is not a smaller version of the enterprise. The risks are different, and so are the failure modes:

• No integration muscle in-house. The team that's brilliant at running the business has never run a merger. There's no IMO playbook on the shelf and no bandwidth to build one mid-deal.

• Founder knowledge that isn't written down. In founder-led companies, the operating model lives in a few people's heads. Lose them in the transition and you lose the thesis.

• Speed-to-value pressure from the sponsor. PE timelines don't wait. Every month integration drifts is a month of EBITDA capture and multiple expansion you don't get back.

• Culture collision nobody planned for. Two ways of working, two comp philosophies, two definitions of "how we do things." Unmanaged, this is where retention and customer confidence quietly erode.

Generic strategy firms treat these as afterthoughts. We treat them as the work.

How Stonehill drives integration value

We run integration as a disciplined, design-led program—not a status meeting. Our Design Thinking foundation means we start with the people and processes that actually create value, then build the structure around them.

Integration Management Office (IMO), stood up fast

‍We install the operating system for the deal: governance, workstream charters, synergy tracking, decision rights, and a single source of truth. Leadership gets visibility and momentum from week one.

• Synergy capture you can actually bank - We translate the deal model into a tracked, owned, time-phased plan—cost and revenue synergies with named owners, baselines, and milestones tied to the value thesis. No more synergies that exist only in the CIM.

• Organizational design and Day 1 readiness - Reporting lines, role clarity, retention of critical talent, and a clean Day 1 that signals stability to employees and customers alike.

• Operating model and process integration - We rationalize two ways of working into one—mapping core processes, eliminating redundancy, and standing up the combined-company operating model that the synergy case assumes.

• Change management and communications - We manage the human side deliberately: stakeholder mapping, leadership alignment, and communications that keep your best people and your most important customers on board through the transition.

• Carve-out and TSA advisory - When the deal is a carve-out, we manage Transition Service Agreements end to end—standing up standalone capability, exiting the TSA on time, and avoiding the trap of stranded costs.

Who we work with

• Private equity sponsors and their portfolio companies capturing synergies and protecting the value thesis post-close

• Founder-led companies integrating their first acquisition without a playbook of their own

• Corporate acquirers in the $50M–$1B revenue range who need integration done right the first time

• Carve-outs and divestitures navigating TSAs and standalone readiness

‍Don't let the value walk out the door

‍The window to capture deal value is short, and it's open right now. Let's talk before integration starts costing you the thesis.